The present invention relates to a method and apparatus for detecting defects in condoms, protective gloves and other similar products and more particularly to a method and apparatus for detecting defects in condoms, protective gloves and other similar products using electrostatic ions of a gas.
Condoms and protective gloves, i.e. gloves used for health care purposes, are very often made of latex or vinyl and fabricated on a mandrel. In the manufacturing of such products, a mandrel of the desired shape is dipped into a container having a supply of the material from which the product is to be made, the material being in liquid form. After a predetermined period of time, the mandrel is withdrawn from the container. The product which has been formed on the mandrel is then allowed to dry and be cured.
As can be appreciated, it is extremely important that protective gloves, condoms and other similar products be free of defects; that is, have no holes or tears or any areas of weakness which may produce holes or tears during use.
One way that has been employed in the past to test for holes or tears in condoms during the manufacture thereof has been to place a condom to be tested on a metallic mandrel (or use a metallic mandrel to fabricate the condom), place the metallic mandrel with the condom on it into a metal container filled with a liquid electrolyte, establish a voltage difference between the container and the metallic mandrel and then measure the resulting current flow, if any, in the mandrel. If there are any holes or tears in the condom, current will flow through the container and the mandrel, the current being carried between the container and the mandrel through the ions in the liquid electrolyte. On the other hand, if there are no holes or tears in the condom there will be no current flow since the condom will serve as an electrical insulator between the mandrel and the electrolyte. One disadvantage with this testing arrangement is that the condom becomes wet when it is immersed In the liquid electrolyte and as a result has to be dried before it can be packaged for later use. This additional step of drying the condom is time consuming and costly. Another disadvantage with this testing arrangement is that because of the skin surface tension and viscosity of the liquid electrolyte, holes or tears in the condom will only be detected that are above a certain minimum size. If the hole or tear is below that certain minimum size, the liquid will not pass through and come into contact with the mandrel. Consequently, there will be no current flow through the mandrel. Still another disadvantage with this testing procedure Is that it is not used to test each and every condom that is being produced, but, rather, only selected condoms. As is apparent, this arrangement is not very satisfactory since it is important that every condom that is going to be used be tested and not merely selected condoms. Also, this testing procedure has only been used in detecting holes or tears and not for monitoring thickness.
Another testing procedure that has been employed in the past to detect defects in condoms during the manufacture thereof has been to remove a condom from the production line, fill it with a liquid and then squeeze it until it breaks. As can be appreciated this procedure is only a quality control type of test rather than a test for each and every condom being manufactured. Also, it is a destructive type of test in that the condom so tested cannot be subsequently put into use.
Accordingly, it is an object of this invention to provide a new and improved method and apparatus for detecting defects In condoms, protective gloves and other similar products.
It is another object of this invention to provide a method and apparatus for detecting defects in condoms, protective gloves and other similar products which does not involve the use of any liquids.
It is still another object of this invention to provide a method and apparatus for detecting defects In condoms, protective gloves and other similar products which can be performed on each product while it is on the production line.
It is yet still another object of this invention to provide a method and apparatus for detecting defects In condoms, protective gloves and other similar products in a very short period of time.
It is a further object of this invention to provide a method and apparatus for detecting defects in condoms, protective gloves and other similar products without moving it to a separate testing station.
It is another object of this invention to provide a method and apparatus for detecting defects in condoms, protective gloves and other similar products without having to touch the product.
It is still another object of this invention to provide a method and apparatus for detecting holes and/or tears in condoms, protective gloves and other similar products.
It is yet still another object of this invention to provide a method and apparatus for monitoring the thickness of condoms, protective gloves and other similar products during the manufacture thereof.
It is a further object of this invention to provide a method for detecting defects in condoms, protective gloves and other similar products which is non-destructive.